<head>
    <meta charset="utf-8" />
    <title>划线属性</title>
    <!-- 
        text-decoration 属性规定添加到文本的修饰。
     -->
    <style>
        /* span {
            text-decoration: underline;
        } */

        #oneClass {
            text-decoration: line-through;
        }
    </style>

<body>
    <p id="one">所在城市:<span>北京</span></p>
    <p id="two">原价:<span id="oneClass">15</span>,现价9.9!</p>
</body>

</html>